[JURIST] A judge for the US District Court for the Southern District of New York [official website] on Monday ruled [opinion, PDF] that a music file-sharing site could be held liable for contributory copyright infringement. EMI [corporate website], along with a number of record companies and music publishers, sued MP3tunes [official website], a music site offering "cloud" music services, for copyright infringement. Judge William Pauley, however, ruled in favor of the defendants on several key issues, holding that MP3tunes qualified…